In 1951, [[GarrettDavid SimpsonA. Huffman]] and his [[MIT]] [[information theory]] classmates were given the choice of a term paper or a final [[exam]]. The professor, [[Robert M. Fano]], assigned a [[term paper]] on the problem of finding the most efficient binary code. Huffman, unable to prove any codes were the most efficient, was about to give up and start studying for the final when he hit upon the idea of using a frequency-sorted [[binary tree]] and quickly proved this method the most efficient.<ref>{{Cite journal | last1 = Huffman | first1 = Ken | title = Profile: David A. Huffman: Encoding the "Neatness" of Ones and Zeroes | journal = [[Scientific American]] | pages = 54–58 | year = 1991 | url = http://www.huffmancoding.com/my-uncle/scientific-american}}</ref>
In doing so, Huffman outdid Fano, who had worked with [[Claude Shannon]] to develop a similar code. Building the tree from the bottom up guaranteed optimality, unlike the top-down approach of [[Shannon–Fano coding]].
